The common brushtail possum (Trichosurus vulpecula), introduced from Australia about 150 years ago, has become a major pest threatening the native biota of New Zealand. It is also an important disease vector, acting as a wildlife reservoir of infection. Conventional methods of control have had little effect on reducing the national population, so there is a quest to find more effective and humane methods. This has led to an upsurge in research aimed at increasing our knowledge of the biology of this marsupial, with an attendant increase in requirements for access to colony-housed animals.

Possums kept for research purposes have often been housed in individual cages, and several colonies have experienced high mortality rates. After capture, possums have shown inappetence, weight loss and a predisposition to infection, suggesting that this species is susceptible to post-capture stress. For our reproductive studies, research animals are only useful if maintained under conditions that ensure behavioural and physiological processes remain normal. We have adopted an ‘animal husbandry’ approach for our possum colony, where social interaction and the ability to exhibit instinctive behaviour patterns are considered as important as adequate nutrition and housing.

In this colony, group-housed possums show no signs of post-capture stress, and mortality rate has been less than one per cent (of > 600 animals housed to date). Virtually all possums gain weight over the first month of captivity. Procedures for monitoring, handling and the collection of data from these animals, are carried out with little apparent stress to either animals or staff.